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command.coffee

The coffee utility. Handles command-line compilation of CoffeeScript into various forms: saved into .js files or printed to stdout, piped to JavaScript Lint or recompiled every time the source is saved, printed as a token stream or as the syntax tree, or launch an interactive REPL.

External dependencies.

fs             = require 'fs'
path           = require 'path'
helpers        = require './helpers'
optparse       = require './optparse'
CoffeeScript   = require './coffee-script'
{spawn, exec}  = require 'child_process'
{EventEmitter} = require 'events'

Allow CoffeeScript to emit Node.js events.

helpers.extend CoffeeScript, new EventEmitter

printLine = (line) -> process.stdout.write line + '\n'
printWarn = (line) -> process.binding('stdio').writeError line + '\n'

The help banner that is printed when coffee is called without arguments.

BANNER = '''
  Usage: coffee [options] path/to/script.coffee
         '''

The list of all the valid option flags that coffee knows how to handle.

SWITCHES = [
  ['-c', '--compile',         'compile to JavaScript and save as .js files']
  ['-i', '--interactive',     'run an interactive CoffeeScript REPL']
  ['-o', '--output [DIR]',    'set the directory for compiled JavaScript']
  ['-j', '--join [FILE]',     'concatenate the scripts before compiling']
  ['-w', '--watch',           'watch scripts for changes, and recompile']
  ['-p', '--print',           'print the compiled JavaScript to stdout']
  ['-l', '--lint',            'pipe the compiled JavaScript through JavaScript Lint']
  ['-s', '--stdio',           'listen for and compile scripts over stdio']
  ['-e', '--eval',            'compile a string from the command line']
  ['-r', '--require [FILE*]', 'require a library before executing your script']
  ['-b', '--bare',            'compile without the top-level function wrapper']
  ['-t', '--tokens',          'print the tokens that the lexer produces']
  ['-n', '--nodes',           'print the parse tree that Jison produces']
  [      '--nodejs [ARGS]',   'pass options through to the "node" binary']
  ['-v', '--version',         'display CoffeeScript version']
  ['-h', '--help',            'display this help message']
]

Top-level objects shared by all the functions.

opts         = {}
sources      = []
contents     = []
optionParser = null

Run coffee by parsing passed options and determining what action to take. Many flags cause us to divert before compiling anything. Flags passed after -- will be passed verbatim to your script as arguments in process.argv

exports.run = ->
  parseOptions()
  return forkNode()                      if opts.nodejs
  return usage()                         if opts.help
  return version()                       if opts.version
  loadRequires()                         if opts.require
  return require './repl'                if opts.interactive
  return compileStdio()                  if opts.stdio
  return compileScript null, sources[0]  if opts.eval
  return require './repl'                unless sources.length
  if opts.run
    opts.literals = sources.splice(1).concat opts.literals
  process.ARGV = process.argv = process.argv.slice(0, 2).concat opts.literals
  process.argv[0] = 'coffee'
  process.execPath = require.main.filename
  compileScripts()

Asynchronously read in each CoffeeScript in a list of source files and compile them. If a directory is passed, recursively compile all '.coffee' extension source files in it and all subdirectories.

compileScripts = ->
  for source in sources
    base = path.join(source)
    compile = (source, topLevel) ->
      path.exists source, (exists) ->
        throw new Error "File not found: #{source}" if topLevel and not exists
        fs.stat source, (err, stats) ->
          throw err if err
          if stats.isDirectory()
            fs.readdir source, (err, files) ->
              for file in files
                compile path.join(source, file)
          else if topLevel or path.extname(source) is '.coffee'
            fs.readFile source, (err, code) ->
              if opts.join
                contents[sources.indexOf source] = code.toString()
                compileJoin() if helpers.compact(contents).length > 0
              else
                compileScript(source, code.toString(), base)
            watch source, base if opts.watch and not opts.join
    compile source, true

Compile a single source script, containing the given code, according to the requested options. If evaluating the script directly sets __filename, __dirname and module.filename to be correct relative to the script's path.

compileScript = (file, input, base) ->
  o = opts
  options = compileOptions file
  try
    t = task = {file, input, options}
    CoffeeScript.emit 'compile', task
    if      o.tokens      then printTokens CoffeeScript.tokens t.input
    else if o.nodes       then printLine CoffeeScript.nodes(t.input).toString().trim()
    else if o.run         then CoffeeScript.run t.input, t.options
    else
      t.output = CoffeeScript.compile t.input, t.options
      CoffeeScript.emit 'success', task
      if o.print          then printLine t.output.trim()
      else if o.compile   then writeJs t.file, t.output, base
      else if o.lint      then lint t.file, t.output
  catch err
    CoffeeScript.emit 'failure', err, task
    return if CoffeeScript.listeners('failure').length
    return printLine err.message if o.watch
    printWarn err.stack
    process.exit 1

Attach the appropriate listeners to compile scripts incoming over stdin, and write them back to stdout.

compileStdio = ->
  code = ''
  stdin = process.openStdin()
  stdin.on 'data', (buffer) ->
    code += buffer.toString() if buffer
  stdin.on 'end', ->
    compileScript null, code

After all of the source files are done being read, concatenate and compile them together.

compileJoin = ->
  code = contents.join '\n'
  compileScript opts.join, code, opts.join

Load files that are to-be-required before compilation occurs.

loadRequires = ->
  realFilename = module.filename
  module.filename = '.'
  require req for req in opts.require
  module.filename = realFilename

Watch a source CoffeeScript file using fs.watchFile, recompiling it every time the file is updated. May be used in combination with other options, such as --lint or --print.

watch = (source, base) ->
  fs.watchFile source, {persistent: true, interval: 500}, (curr, prev) ->
    return if curr.size is prev.size and curr.mtime.getTime() is prev.mtime.getTime()
    fs.readFile source, (err, code) ->
      throw err if err
      compileScript(source, code.toString(), base)

Write out a JavaScript source file with the compiled code. By default, files are written out in cwd as .js files with the same name, but the output directory can be customized with --output.

writeJs = (source, js, base) ->
  filename  = path.basename(source, path.extname(source)) + '.js'
  srcDir    = path.dirname source
  baseDir   = if base is '.' then srcDir else srcDir.substring base.length
  dir       = if opts.output then path.join opts.output, baseDir else srcDir
  jsPath    = path.join dir, filename
  compile   = ->
    js = ' ' if js.length <= 0
    fs.writeFile jsPath, js, (err) ->
      if err
        printLine err.message
      else if opts.compile and opts.watch
        console.log "#{(new Date).toLocaleTimeString()} - compiled #{source}"
  path.exists dir, (exists) ->
    if exists then compile() else exec "mkdir -p #{dir}", compile

Pipe compiled JS through JSLint (requires a working jsl command), printing any errors or warnings that arise.

lint = (file, js) ->
  printIt = (buffer) -> printLine file + ':\t' + buffer.toString().trim()
  conf = __dirname + '/../extras/jsl.conf'
  jsl = spawn 'jsl', ['-nologo', '-stdin', '-conf', conf]
  jsl.stdout.on 'data', printIt
  jsl.stderr.on 'data', printIt
  jsl.stdin.write js
  jsl.stdin.end()

Pretty-print a stream of tokens.

printTokens = (tokens) ->
  strings = for token in tokens
    [tag, value] = [token[0], token[1].toString().replace(/\n/, '\\n')]
    "[#{tag} #{value}]"
  printLine strings.join(' ')

Use the OptionParser module to extract all options from process.argv that are specified in SWITCHES.

parseOptions = ->
  optionParser  = new optparse.OptionParser SWITCHES, BANNER
  o = opts      = optionParser.parse process.argv.slice 2
  o.compile     or=  !!o.output
  o.run         = not (o.compile or o.print or o.lint)
  o.print       = !!  (o.print or (o.eval or o.stdio and o.compile))
  sources       = o.arguments

The compile-time options to pass to the CoffeeScript compiler.

compileOptions = (filename) -> {filename, bare: opts.bare}

Start up a new Node.js instance with the arguments in --nodejs passed to the node binary, preserving the other options.

forkNode = ->
  nodeArgs = opts.nodejs.split /\s+/
  args     = process.argv[1..]
  args.splice args.indexOf('--nodejs'), 2
  spawn process.execPath, nodeArgs.concat(args),
    cwd:        process.cwd()
    env:        process.env
    customFds:  [0, 1, 2]

Print the --help usage message and exit. Deprecated switches are not shown.

usage = ->
  printLine (new optparse.OptionParser SWITCHES, BANNER).help()

Print the --version message and exit.

version = ->
  printLine "CoffeeScript version #{CoffeeScript.VERSION}"